When Master Sample Encoder is selected as nvenc, it will have convert failure due to using h264_nvenc while encoding a 10 bit source video.
I think the possible solutions is to switch to hevc_nvenc, or use cpu to encode the video when detected a 10 bit source video.
Creating master sample from 5 segments...
FATAL error in CQ search: RuntimeError: Master sample creation failed: ffmpeg version 2025-10-01-git-1a02412170-full_build-www.gyan.dev Copyright (c) 2000-2025 the FFmpeg developers
built with gcc 15.2.0 (Rev8, Built by MSYS2 project)
configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-lcms2 --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-libdvdnav --enable-libdvdread --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libopenjpeg --enable-libquirc --enable-libuavs3d --enable-libxevd --enable-libzvbi --enable-liboapv --enable-libqrencode --enable-librav1e --enable-libsvtav1 --enable-libvvenc --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxeve --enable-libxvid --enable-libaom --enable-libjxl --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-dxva2 --enable-d3d11va --enable-d3d12va --enable-ffnvcodec --enable-libvpl --enable-nvdec --enable-nvenc --enable-vaapi --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-openal --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-liblc3 --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint --enable-whisper
libavutil 60. 13.100 / 60. 13.100
libavcodec 62. 16.100 / 62. 16.100
libavformat 62. 6.100 / 62. 6.100
libavdevice 62. 2.100 / 62. 2.100
libavfilter 11. 9.100 / 11. 9.100
libswscale 9. 3.100 / 9. 3.100
libswresample 6. 2.100 / 6. 2.100
Input #0, matroska,webm, from 'D:/Documents/VHS_Simulation/out_ntsc1.mkv':
Metadata:
creation_time : 2025-10-20T01:35:36.978378Z
ENCODER : Lavf62.6.100
Duration: 00:02:43.17, start: 0.000000, bitrate: 274174 kb/s
Stream #0:0: Video: ffv1, yuv444p10le(tv, smpte170m/bt709/smpte170m, progressive), 1920x486, SAR 27:80 DAR 4:3, 29.97 fps, 29.97 tbr, 1k tbn (default)
Metadata:
TITLE : Video
Stream #0:1(eng): Audio: flac, 192000 Hz, stereo, s32 (24 bit), start 0.007000 (default)
Metadata:
TITLE : Audio
Incompatible pixel format 'yuv444p10le' for codec 'h264_nvenc', auto-selecting format 'yuv444p10msble'
Stream mapping:
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
concat:out:v0 -> Stream #0:0 (h264_nvenc)
Press [q] to stop, [?] for help
[h264_nvenc @ 00000168f2dd00c0] The selected preset is deprecated. Use p1 to p7 + -tune or fast/medium/slow.
[h264_nvenc @ 00000168f2dd00c0] 10 bit encode not supported
[h264_nvenc @ 00000168f2dd00c0] No capable devices found
[vost#0:0/h264_nvenc @ 00000168f2a0b440] [enc:h264_nvenc @ 00000168f29cdbc0] Error while opening encoder - maybe incorrect parameters such as bit_rate, rate, width or height.
[fc#0 @ 00000168f29f5c40] Error sending frames to consumers: Generic error in an external library
[fc#0 @ 00000168f29f5c40] Task finished with error code: -542398533 (Generic error in an external library)
[fc#0 @ 00000168f29f5c40] Terminating thread with return code -542398533 (Generic error in an external library)
[vost#0:0/h264_nvenc @ 00000168f2a0b440] [enc:h264_nvenc @ 00000168f29cdbc0] Could not open encoder before EOF
[vost#0:0/h264_nvenc @ 00000168f2a0b440] Task finished with error code: -22 (Invalid argument)
[vost#0:0/h264_nvenc @ 00000168f2a0b440] Terminating thread with return code -22 (Invalid argument)
[out#0/matroska @ 00000168f2a0bac0] Nothing was written into output file, because at least one of its streams received no packets.
frame= 0 fps=0.0 q=0.0 Lsize= 0KiB time=N/A bitrate=N/A speed=N/A elapsed=0:00:00.47
Conversion failed!
Traceback (most recent call last):
File "Auto Target Encoder.pyw", line 2585, in find_best_cq_optimized
master_sample_data, timings['sample_creation_time'] = create_master_sample_in_memory(
File "Auto Target Encoder.pyw", line 2376, in create_master_sample_in_memory
raise RuntimeError (f"Master sample creation failed: {result .stderr .decode ('utf-8',errors ='ignore')}")
RuntimeError: Master sample creation failed: ffmpeg version 2025-10-01-git-1a02412170-full_build-www.gyan.dev Copyright (c) 2000-2025 the FFmpeg developers
built with gcc 15.2.0 (Rev8, Built by MSYS2 project)
configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-lcms2 --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-libdvdnav --enable-libdvdread --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libopenjpeg --enable-libquirc --enable-libuavs3d --enable-libxevd --enable-libzvbi --enable-liboapv --enable-libqrencode --enable-librav1e --enable-libsvtav1 --enable-libvvenc --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxeve --enable-libxvid --enable-libaom --enable-libjxl --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-dxva2 --enable-d3d11va --enable-d3d12va --enable-ffnvcodec --enable-libvpl --enable-nvdec --enable-nvenc --enable-vaapi --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-openal --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-liblc3 --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint --enable-whisper
libavutil 60. 13.100 / 60. 13.100
libavcodec 62. 16.100 / 62. 16.100
libavformat 62. 6.100 / 62. 6.100
libavdevice 62. 2.100 / 62. 2.100
libavfilter 11. 9.100 / 11. 9.100
libswscale 9. 3.100 / 9. 3.100
libswresample 6. 2.100 / 6. 2.100
Input #0, matroska,webm, from 'D:/Documents/VHS_Simulation/out_ntsc1.mkv':
Metadata:
creation_time : 2025-10-20T01:35:36.978378Z
ENCODER : Lavf62.6.100
Duration: 00:02:43.17, start: 0.000000, bitrate: 274174 kb/s
Stream #0:0: Video: ffv1, yuv444p10le(tv, smpte170m/bt709/smpte170m, progressive), 1920x486, SAR 27:80 DAR 4:3, 29.97 fps, 29.97 tbr, 1k tbn (default)
Metadata:
TITLE : Video
Stream #0:1(eng): Audio: flac, 192000 Hz, stereo, s32 (24 bit), start 0.007000 (default)
Metadata:
TITLE : Audio
Incompatible pixel format 'yuv444p10le' for codec 'h264_nvenc', auto-selecting format 'yuv444p10msble'
Stream mapping:
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
Stream #0:0 (ffv1) -> trim:default
concat:out:v0 -> Stream #0:0 (h264_nvenc)
Press [q] to stop, [?] for help
[h264_nvenc @ 00000168f2dd00c0] The selected preset is deprecated. Use p1 to p7 + -tune or fast/medium/slow.
[h264_nvenc @ 00000168f2dd00c0] 10 bit encode not supported
[h264_nvenc @ 00000168f2dd00c0] No capable devices found
[vost#0:0/h264_nvenc @ 00000168f2a0b440] [enc:h264_nvenc @ 00000168f29cdbc0] Error while opening encoder - maybe incorrect parameters such as bit_rate, rate, width or height.
[fc#0 @ 00000168f29f5c40] Error sending frames to consumers: Generic error in an external library
[fc#0 @ 00000168f29f5c40] Task finished with error code: -542398533 (Generic error in an external library)
[fc#0 @ 00000168f29f5c40] Terminating thread with return code -542398533 (Generic error in an external library)
[vost#0:0/h264_nvenc @ 00000168f2a0b440] [enc:h264_nvenc @ 00000168f29cdbc0] Could not open encoder before EOF
[vost#0:0/h264_nvenc @ 00000168f2a0b440] Task finished with error code: -22 (Invalid argument)
[vost#0:0/h264_nvenc @ 00000168f2a0b440] Terminating thread with return code -22 (Invalid argument)
[out#0/matroska @ 00000168f2a0bac0] Nothing was written into output file, because at least one of its streams received no packets.
frame= 0 fps=0.0 q=0.0 Lsize= 0KiB time=N/A bitrate=N/A speed=N/A elapsed=0:00:00.47
Conversion failed!
ML predicts encoding will take ~1m 17s (low confidence)
🚀 Starting final encode with SVT_AV1 (CQ/CRF: 0)...
Reached 100%, waiting for finalization...
Waiting for FFmpeg to exit...
Verifying output file...
✅ Source kept, saved 98.1%
When Master Sample Encoder is selected as nvenc, it will have convert failure due to using h264_nvenc while encoding a 10 bit source video.
I think the possible solutions is to switch to hevc_nvenc, or use cpu to encode the video when detected a 10 bit source video.